INTRODUCTION:
Vascular anomalies can be divided into two large groups of alterations and the International Society for the Study of Vascular Abnormalities (ISSVA) differentiates them according to their clinical course and anatomical, histological and pathophysiological characteristics (1-3). On one hand, vascular malformations, constitute a group of blood vessel abnormalities generated by disorganized angiogenesis secondary to mutations in the vascular endothelial growth factor (VEGF) receptor, are present at birth and progress throughout life (arteriovenous fistulas, spot port wine, nevus flammeus, among others) (3,4). On the other hand, vascular tumors are generated by the abnormal proliferation of the endothelium with aberrant architecture of the blood vessels, generating masses that not only generate aesthetic problems but can also generate functional disorders in fetuses and newborns (2,4).
Some alterations at the vascular level may be the result of the lack of regression of some primitive vessels of the vascular system, as is the case of the persistent left superior vena cava (PLSVC), which constitutes the most common thoracic venous variation and is generated by the persistence of the left anterior cardinal vena cava which by the eighth week of embryogenesis should become the left anterior cardinal ligament (5–7). In isolated cases this alteration is considered a benign condition with a low probability of aneuploidy, associated abnormalities and adverse perinatal outcome, however some studies have identified that its association with other alterations can increase these events (5).